Trussed ladder



No. 607,665. Patented July l9,l898. F. S. SEAGRAVE.

TRUSSED LADDER.

(Applimtinnfllarlpr. 28, 189B Unrren Starts aren't Orricn.

FREDERIO S. SEAGRAVE, OF COLUMBUS, OHIO.

TRUSSED LADDER.

SPECIFICATION forming part of Letters Patent No. 607,665, dated July 19, 1898.

A fi ti fil d April 28, 1898. Serial No. 679,158. (No modeLl v May 22, 1883, and No. 347,648, of August 17,-

The objects of my present invention areto provide a trussed ladder with improved means for clamping the legs and trusses of the ladder-frame together, to so construct and apply.

said connecting or clamping devices as to obviate any tendency toward the connected parts working loose, and at the same time provide improved means for compensating for shrinkage of the adjoining parts and retaining the struts and legs rigidly connected one with the other, and to provide other improvements in details of construction and arrangement of parts, which will be more fully pointed out hereinafter. the manner illustrated in the accompanying drawings, in which- Figure 1 is a view in perspective of atrussed ladder having my improvements thereon. Fig. 2 is a detail view in elevation of one of the clamping-yokes. Fig. 3 is a detail View in perspective of aportion of one of the arms of said clamping-yoke, and Fig.4 is a similar View showing a modified form of transverse rib or lug.

Similar numerals refer to similar parts throughout the several views.

1 represents theparallel legs of a ladder, which are connected in the usual manner by transverse rounds 2.

3 represents the trussed bars or truss framepieces, which are bowed downwardly from and have their ends rigidly connected with the end portions of the legs 1 in the manner hereinafter described.

As indicated in the drawings, the legs and trusses are connected in the usual manner and at desirable intervals by struts i.

In joining the end portions of the struts and legs I employ metallic clamping-yokes These objects I accomplish in 5, which are of the substantially stirrup or U form indicated in the drawings. As shown more clearly in Fig. 2 of the drawings, the parallel arms or members of the clampingyoke gradually decrease in thickness toward their outer ends, and the arms thus formed are provided on their inner sides, preferably at oppositely-located points, with inwardlyprojecting transverse ribs or lugs 6. A clamping-yoke formed as above described is utilized to produce a-rigid connection of the corresponding end portions of a ladder truss and leg by causing the upper side of said truss in its end portion and thelower side of said leg to be embraced by the upper and lower arms of the clamping-yoke, said truss being provided on its outer surface with a transverse recess or groove 7 and said leg being provided with a similar transverse groove or recess 8, which are adapted, as shown in Fig. 1 of the drawings, to receive the ribs or lugs 6 of the clamping-yoke. The corresponding ends of the truss and leg being thus made to fit snugly within the yoke, the substantially parallel arms of said yoke are united through the medium of bolts 9, which pass through the end portions of both the truss and leg.

Heretofore and as set forth in my former patent, No. 7,648, it has been common to connect the truss and leg portions with a wooden dowel-pin, but where this connection has been employed it has been found that when the ladder-framework was subjected to the influence of a dry atmosphere the connected parts displayed a tendency through shrinkage toward working loose and the rigid connection originally imparted to the parts was thus impaired.

Through the medium of my improved clamping device it will readily be seen that the engagement of the transverse ribs of the clamp with the recesses in the framework, together with the clamping action of the yoke upon the parts, will form an exceedinglyrigid connection of the truss and leg ends, and in case of any tendency of the parts to become loose through shrinkage or otherwise it is obvious that by tightening the bolts 9 said parts may be firmly drawn together, thus adding to both the life and utility of the ladderframe.

As indicated in Fig. 4. ot the drawings, I

mayproduce the ribs 6 in an angular or square form instead of the rounded form shown in the remaining figures.

From the construction and application of the yoke herein described it will readily be seen that an exceedingly strong, durable, and neat form of trussed ladder may be produced and that the means employed for connecting the trusses and legs are such as to admit of the same being produced and applied at a reasonable cost.

Having now fully described my invention, What I claim, and desire to secure by Letters Patent, is- 1 In a trussed ladder, the combination With the legs, rounds and trusses, said legs and FREDERIO S. SEAGRAVE.

In presence 0f-- A. L. PHELPS, EDWARD M. TAYLOR. 

